There are many types of radar, and the classification method is also very complicated. Generally military radar. It can usually be classified according to the purpose of the radar, such as early warning radar, search warning radar, guidance command radar, gunsight radar, altimetry radar, battlefield surveillance radar, airborne radar, radio altimetry radar, radar fuze, meteorological radar, navigation control radar , Navigation radar, collision avoidance and enemy identification radar, etc.

The ultrashort wave communication system is composed of terminal stations and relay stations. The terminal station is equipped with a transmitter, receiver, carrier terminal and antenna. Relay stations only have transmitters and receivers in two directions, and corresponding antennas.

The basic factors of the human body's various physiological reactions caused by ultrashort wave are thermal effect and non-thermal effect.